<!DOCTYPE html>
<html>

<head>
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/css/bootstrap.min.css">
    <script src="https://code.jquery.com/jquery-3.2.1.slim.min.js"></script>
    <script src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.bundle.min.js"></script> </head>

<body>
    <div class="jumbotron">
        <h1 class="display-4">Hello, world!</h1>
        <p class="lead">This is a simple hero unit, a simple jumbotron-style component
            for calling extra attention to featured content or information.</p>
        <hr class="my-4"> <!-- my-4是margin-top和margin-bottom -->
        <p>It uses utility classes for typography and spacing to space content
            out within the larger container.</p>
        <p class="lead">
            <a class="btn btn-primary btn-lg" href="#" role="button">Learn more</a>
        </p>
    </div>
</body>

</html>